NEW YORK, Sept 1 (Reuters) - The S&P 500 and the Dow dipped
on Thursday after sluggish monthly factory activity data dented
optimism about the economy and oil prices declined, as investors
exercised caution ahead of a payrolls report on Friday.

A report from the Institute of Supply Management showed U.S.
factory activity contracted for the first time in six months in
August as new orders and production tumbled, but data on the
labor market pointed to a pickup in third quarter economic
growth.

Energy shares, down 0.9 percent, also weighed as oil
prices declined on worries about a supply glut. U.S. crude
was off 3.1 percent at $43.31 a barrel while Brent
shed 2.9 percent to $45.52.

"Both the lower oil prices and the ISM show weakness in the
economy," said Tim Ghriskey, chief investment officer of Solaris
Asset Management in New York.
Continuación...